Revert "Don't include sk keys at all in KEX list" This reverts git commit f972813ecdc7bb981d25b5a63638bd158f1c8e72. The sk algorithms need to remain in the sigalgs list so that they are included in the server-sig-algs ext-info message sent by the server. RFC8308 for server-sig-algs requires that all algorithms are listed (though OpenSSH client 8.4p1 tested doesn't require that)